A tennis player throws a .02 kg ball against the wall at 10m/s. It hits the wall and comes back at -17 m/s. His foot was in contact with the ball for .021 sec. What was the force of the kick? Remember what to do with two velocities.

For waves in the ocean, the medium of the waves is a. air b. water c. energy d. a passing boat

Ethanol has a heat of vaporization of 38.56 kj/mol and a normal boiling point of 78.4 c. what is the vapor pressure of ethanol at 14 c?

Astone is dropped from the upper observation deck of a tower, 250 m above the ground. (assume g = 9.8 m/s2.) (a) find the distance (in meters) of the stone above ground level at time t. h(t) = (b) how long does it take the stone to reach the ground? (round your answer to two decimal places.) s (c) with what velocity does it strike the ground? (round your answer to one decimal place.) m/s (d) if the stone is thrown downward with a speed of 2 m/s, how long does it take to reach the ground? (round your answer to two decimal places.) s